One man creates epic action in "An Iliad," a Homer-inspired play at Capital Repertory Theatre that uses only words and music to conjure the horrors of the Trojan war, from sweeping battles to brutal man-to-man combat, all graphically told and brought to life by actor David Barlow.

A mesmerizing performance and true feat of impassioned acting, it is amplified by the work of the only other person on the stage, cellist Kathleen Bowman, a Saratoga Springs music teacher who composed the score and whose playing becomes a character in itself, as it responds to and comments on the story being recounted.

The 5-year-old play, first presented in Manhattan by its creators, actor Denis O'Hare and director Lisa Peterson, uses one man, simply known as The Poet, to retell Homer's poetic tale of the 10-year siege of Troy by Greek states. (The acclaimed 1990 translation on which the play is based is by the late Princeton scholar Robert Fagles.)

Dressed in casual contemporary clothes and speaking in modern vernacular with occasional flourishes of Homer (some in Greek), The Poet takes us backward from today to the 12th century B.C. The causes of war are complex, The Poet says, but he can simplify: "The point is, Helen's been stolen, and the Greeks have to get her back."

Storming around an excellent set by Bill Clarke that evokes the physical destruction of war, Barlow's poet alternates image-rich narration with blow-by-blow descriptions of individual fights and their injurious toll. He also makes several lists, recitations that become incantations, most movingly when he recounts scores of wars. It's a catalog of human aggression and atrocity from the ancient era to Syria today.

Production notes describe director Margaret E. Hall, who is the assistant to Capital Rep head Maggie Mancinelli-Cahill and is making her main stage directing debut with this show, as working collaboratively with Barlow and Bowman to develop the production. Their interconnected work is obvious, as is their clear vision of the story they've set out to tell.

The Greek gods, described as amusing themselves with human conflict and meddling when it suits them, are pettier than people, and humans aren't much better. Trying to explain why the Greeks spent a decade attacking Troy, The Poet analogizes it to waiting in a checkout line at the supermarket and debating whether to move to another cashier who appears to be faster. He says, "Do you switch lines now? No, goddamn it, I've been here for 20 minutes, I'm gonna wait in this line, I don't care if I wait. And look — I'm not leaving cuz otherwise I've wasted my time."

This is just one version of the story, The Poet tells us, a position reinforced by the indefinite article in the play's title. It has evolved with the tellings and the centuries, but the constant is the obscenity of war, and The Poet is weary. One of the first things he says at the beginning is also the ultimate message by the end: "Every time I sing this song, I hope it's the last time."